Feeding amount

Amelia

So my daughter is formula fed and she is 4 weeks old. A few days ago we increased her amount from 3 oz to 3.5-4 every 3 hrs because she was only going about 2 hrs between feedings and when we only gave her 3 she still acted hungry.

We have increased her to about 4 oz now which seems to satisfy her but then she spits up a lot after she eats. So which cue do I follow - her actions before or after she eats?